1. Field of the Invention
This invention relates generally to portable equipment hoists and, more particularly, to hoists used to lift motorcycles so that they may be more easily serviced.
2. History of the Prior Art
A number of types of motorcycle hoists, or lifts, are in general use. Motorcycle repair shops typically have at least one hydraulic floor hoist. Such hoists are smaller versions of those used to lift automobiles. As a rule, these hoists are expensive and not easily movable. Various portable motorcycle hoists are also available. U.S. Des. Pat. No. 378,155 shows a hydraulic parallelogram motorcycle lift. Mounted on casters, it is readily movable. This lift supports the motorcycle beneath the engine, thereby freeing both wheels for ease of wheel removal. However, the parallelogram mechanism provides limited vertical travel, thereby making it difficult to work on the engine in a standing position. U.S. Pat. No. 5,518,224 shows another type of portable motorcycle lift that looks much like a small table when in the raised position. The legs are attached to a base in parallelogram fashion. The platform, when raised by means of a foot lever, attains a stable over-center position in the raised position. A locking device secures the platform in the over-center position. Like the lift of the previous patent, it lifts the motorcycle beneath the engine, thereby permitting simultaneous removal of both wheels. Also, as with the lift of the previous patent, vertical travel is limited. Other portable motorcycle hoists lift the cycle by its wheels, thereby hampering the removal of wheels and the changing and repairing of tires.
Off-road motorcycle racing is a very popular sport. Most of the participants are individuals operating with limited budgets and must tune and repair their own cycles. Tuning and repair of the motorcycle in the pits at the site of the race is usually a necessity if the bike is to be competitive. There is a need for a cycle hoist which:
(1) Is relatively inexpensive;
(2) Is simple to operate and maintain;
(3) Requires only minimal strength to raise the cycle;
(4) Is stable when the cycle is raised to the maximum height;
(3) Provides sufficient vertical displacement that the engine can be adjusted in a standing position;
(4) Provides unfettered access to both sides of the bike in the raised position;
(5) Permits removal of both wheels while in the raised position; and
(6) May be readily disassembled to facilitate transport.
The present invention fills the heretofore expressed need by providing a new and novel hoist for motorcycles that is relatively inexpensive, simple to operate and maintain, requires little or no strength to raise the cycle, is stable when the cycle is in a raised position, has sufficient vertical travel so that the cycle""s engine may be adjusted in a standing position, provides unfettered access to both sides of the cycle when in the fully-elevated position, permits removal of both wheels when the cycle is elevated, and may be easily and quickly disassembled to facilitate transport.
The new motorcycle hoist has a main frame assembly which includes a pair of vertically-oriented parallel channel beams rigidly affixed to both an upper cross brace and to a base member. The pair of channel beams provide a caged track for a trolley which is movably slidable therein between a lowermost position and an uppermost position. The trolley is fitted with a plurality of guide wheels to minimize sliding friction within the caged track. A cradle assembly, adapted to support a motorcycle beneath its engine, is attached to the trolley. Attachment may be made with welds, threaded fasteners, or other suitable means. The base member may be unitary, or it may be partially disassemblable to facilitate transport and storage. The base member may also incorporate casters to facilitate the repositioning of a supported cycle.
A first main embodiment of the invention includes a first pulley mounted on the upper cross brace, a second pulley mounted on the trolley, and an electric-motor-driven winch mounted on the base member. A cable wrapped around the take-up spool of the winch is routed from the takeup spool, around the first pulley, around the second pulley, and to the upper cross brace where it is securely fastened. On-board power for the winch may be provided in the form of a battery preferably mounted on the base member. A polarity-reversing switch provides up and down control for movement of the trolley.
A second main embodiment of the invention substitutes a hand-powered winch for the motor-driven winch. For the sake of convenience, the hand-powered winch is mounted on a mid-span brace which interconnects the vertical channel beams.
A third main embodiment of the invention substitutes a pneumatic cylinder for the winch and cable system. The cylinder may be powered by compressed air provided by a compressor, or it may be provided by a disposable CO2 cartridge. A release valve allows the system to be depressurized in order to lower the cycle from a raised position.
A fourth main embodiment of the invention substitutes a hydraulic cylinder for the pneumatic cylinder. Operation of hydraulic cylinders is similar to the operation of pneumatic cylinders, is well known in the art, and will not be covered herein.
The invention may also be adapted to mount on the side of a trailer. For such an application, the cradle may be hinged to rotate from a horizontal position to a vertical position for storage while the trailer is being towed.